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(No Model.) 2 Sheets-Sheet 2. R. J. BAKER. AUTOMATIC FIRE ALARM..

No. 600,765. Patented Mar. 15,1898.

Ml 111|] AMA] 'vll A A manif ROBERT J. BAKER, OF BALTIMORE, MARYLAND,ASSIGN OR OF ONE-THIRD TO JOSEPH MAISCH, OF SAME PLACE.

AUTOMATIC FIREALARM.

SPECIFICATION forming part of Letters Patent No. 600,765, dated March15, 1898.

Applie ation tiled April 2 8, 1 89 7.

To @ZZ whom t may concern.-

Be it known that I, ROBERT J BAKER, residing at Baltimore, in the Stateof Maryland, have invented a new and useful Automatic Fire-Alarm, ofwhich the following is a specication.

My invention relates to an automatic lirealarm for use in warehouses,factories, hotels, dwellings, &c., and it may be used in conjunctionwith the local lire-alarm system or not, as desired.

The object of my invention is to provide an automatic alarm which willindicate in what portion of the building lire has been started and atthe same time sound an alarm and, if used in conjunction with the localfire system, will through suitable mechanism sound an alarm at thefire-station and by the alarm indicate in what districtthe alarm wasturned in. I accomplish this object by providing a suitable alarm placedin a box of any dimension and locating in the circuit of the alarm anindicator. Throughout the several rooms of a house I locate Wiresleading from the indicator and normally have the wire in open circuit. Ialso place thermostats in position in the wire circuit, so that whenthere is any great amount of heat in the room they will act to close thecircuit and sound the alarm. I also provide automatic means inconnection with the box whereby the hinged front will drop to expose theindicator, and also, if the alarm is used in connection with the locallire system, the falling front will permit suitable mechanism to operateto sound an alarm at the lire-station.

My invention, broadly stated, consists of the above arrangement of partsand of certain details of novel construction of the several parts, allof which will be hereinafter more fully described, and specificallypointed out in the claims.

In order that my invention may be fully understood, I will proceed todescribe the same, with reference to the accompanying drawings, inwhich- Figure l is a front elevation of the automatic alarm with thehinged front down to disclose the indicator and the several parts of thealarm. Fig. 2 is a transverse sectional view of the box with the hingedfront in closed Serial No. 634,225. (No model.)

position. Fig. 3 is a detail' View of the thermostat used in the wirecircuit throughout the several views. Fig. 4 is a plan view of the samewith the top removed. Fig. 5 is a fragmentary detail view on an enlargedscale, showing one of the contact-arms of the thermostat, illustratingalso in dotted lines the position it assumes when heated.` Fig.' 6 is adetail sectional view of the mechanism on the dottedA lines 6 6 of Fig.2 used for sounding an alarm in the engine-station. Fig. 7 is adiagrammatic view of the alarm and the manner of wiring a building.

In the said drawings, A represents the box or casing of my automaticalarm, which may be of any desired size or configuration as may be foundconvenient. It is preferably provided with the hinged front B, havingthe word Fire placed on the inside of the front in luminous paint, andthis front is for the purpose hereinafter stated. The casing is alsoprovided with the hinged door O` in one of the other sides, so that themechanism contained in the box can be easily reached or inspected.

In the box or casing A, I preferably locate the several parts of myautomatic alarm,

which is composed of the indicator,the alarmbell and mechanism foroperating it, and the automatic catch for allowing the front to fall. Aswill be seen from Fig. l, the hinged front is in such a'position in thebox that it will fall by gravity when the catch is operated and beassisted in its fall by the weight of the magnets.

The indicator D used in the alarm may be of any desired construction andbe of any size. One wire from each station is passed through a commonopening in the indicatorcasing, `and each wire has two branches Dleading therefrom,which are run to that part of the building which theindicator will designate. The other wires from each station in theindicator are bunched and connected with a common wire K', which leadsto the magnets of the catch.

The alarm is composed of the usual bell E, magnets E', and the clapperE2,which is carried by the armature F. The arrangement of clapper andarmature which I use in this connection is as follows: The armature F isIOO hinged at one end to the box or casing, as shown at F', while itsother end F2 is bent downward and opens and closes a switch, so that thealarm will be continuously sounded. The switch consists of the twosprings G and G', secured at one of their ends in any desired manner andhaving their contacting ends in the path of the end F2. In will beunderstood (see'Fig. 7 that one pole Z from the battery is connectedwith one pole of the magnets E', and the wire leading from the magnetsE' is connected with one of the springs,while the other spring G' isconnected by a wire G2 with the magnets of the catch. Thus it will beseen that when the armature is attracted to the magnets the end F2 willdescend upon the spring G to break the circuit, so that the spring G'lwill pull the clapper E2 against the bell. Of course as the end F2 ismoved away the circuit will be completed and the armature drawn downagain. By this means a continuous ringing is kept up.

The automatic catch carried by the hinged front B, and which isoperatedv to allow the front to drop, consists of the magnets I^I,whichare in the circuit of the wire G2, and the armature H',which engages thehook H2 on top of the box. The armature H' has the springs H3, carriedby the pins I, normally bearing against it to keep it in engagement withthe hook. The pins I are carried by the guard I', which holds themagnets in place on the hinged front.

I3 represents a slotted plate which allows for the adjustment of themagnets toward or away from the armature.

It will be understood that the several parts above described aresuitably located in the box so that when a iire is indicated they willoperate.

The manner of connecting the several parts so that they will operate isas follows: One pole of the battery is connected with one pole of thebell-magnets E' by the wire Z, while indicator of the several stations.

the other wire Z' of the battery' is carried to the several rooms of thebuilding, as seen in Fig. 7. After leaving the magnets E' the circuitpasses through the springs G and G' into the magnets H of the catchthrough the wire G2, and after leaving the magnets H it passes throughthe wire K', which is connected with the wires of one pole of themagnets of the The other wire from each station-indicator, as abovestated, is passed through an opening in the casing,which bunches them,and each of these wires is provided with two branches, which lead tothat part of the building designated by the indicator. These two wiresand battery-wire Z' run to each portion of the building, and at thosepoints I locate my improved form of thermostat, which is shown in Figs.3, 4, and 5. This thermostat consists of a back plate L, of porcelain orother non-conducting material, edge blocks having grooves in theirvupper surfaces, in which are located the wires from the battery andindicator, the contacting mechanism, and a perforated cover of porcelainor other non-conducting material. The contacting mechanism consists ofan iron bow L5, in contact with the battery-wire, having arms L2reaching to a position adjacent to the indicator-wires. A set-screwregulates the normal position of these arms. On the inner side of eacharm is rigidly secured a bar L3, of copper or some metal which, whilebeing a conductor of electricity, is expansible to a greater extent thaniron under the application of heat. These bars L3 are provided at theirouter ends with angular toes or contactpoints M. When, under ordinarytemperature, the normal position of the contact-points M is out. ofcontact with the indicator-points, the application of a degree of heatin excess of a safe temperature will cause the outer ends of arms L2 andthe bars L3 to become curved outward owing to the greater expansion ofbars L3, which, as clearly shown in dotted lines in Fig. 6, will lcausethe toes or points M to-contact with the indicator-wires, thus closingthe circuit through the indicator and sounding an alarm.

It will be seen from the foregoing that I have provided an insulatingmeans in connection with a thermostat and that owing to the arrangementthere will be no uninsulated wire exposed, thereby avoiding accidentalfires often caused by the uninsulated portion of the wire coming intocontact with an electric wire, which causes a spark. The advantage ofhaving two wires is that if one should get out of order the other willbe ready to complete the circuit.

So far I have only described that part of my invention which is designedfor use in a building and not in conjunction with the local fire system,and it will be seen from the foregoing description that I have providedan exceed- IOO ingly simple and effective arrangement for indicatingfire in any part of a building. It will also be observed that I havedescribed the several parts arranged in what is known as an opencircuit, and it will be understood that an equally effective resultcould be obtained in a closed circuit.

If it is desired to use my automatic alarm in connection with the localfire system, I provide the usual clockwork system N on the casing, towhich the wires from a battery located in the lire-station areconnected. In the clockwork I provide the wheel N', having the pins N2,which are so arranged as to sound the bell in the engine-house, andwhich is in this circuit, to indicate the number of the individual box,so that the call can be located at once. The wires leading from thebattery in the engine-house terminate in the springarms N3 N4, one ofwhich, N3, is always in contact with the wheel N', while arm N4 is inthe IIO anism by the chain O', so that when the front falls the chainwill unwind and allow the side to drop gradually. In order to hold theclock mechanism when the hinged front is in position, I provide thespring P, which engages one of the train of wheels of the clockmechanism, so that it cannot unwind to sound the fire-alarm.

Q represents a switch for throwing out the arm Nato prevent an alarmbeing sounded` at the engine-house when it is desired to inspect the boxor try the wires in the building.

It will be understood that the alarm proper can be used independently ofthe local system or in connection therewith, or, if preferred, aseparate and distinct circuit can be employed to give an alarm in thefire-station.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination with the door and the casing provided with the catch,of an angular bracket having slotted arms in contact with the door,screws through the slots foradjustably securing the bracket to the door,magnetcoils mounted on the upright arms of the bracket, a bracket, I,secured to the door, provided with openings through which the coils passand smaller side openings, the armature, pins projecting back therefromthrough the side openings of bracket I, and springs arou nd the pins7bearing against the armature and the bracket I to hold the armaturenormally in engagement with the catch, substantially as described.

2. In an automatic fire-alarm, the combination of a box or casingadapted to be secured to a wall, an alarm-bell mounted on a standardsecured to the back of the box or casing,

a pair of magnets mounted on a bracket se cured to the back of thecasing below the bell,

the armature, F, of said magnets, having thev 3. A thermostat,comprising an insulated iron bow in contact with the battery-wire andhaving outwardly-projected arms extending toward the indicator-wires,parallel with the battery-wires, bars of different expansibility 'lyingagainst and rigidly secured to the inside of said arms and provided withangular toes or contact-points adjacent to the indicatorwires, and aset-screw for adjusting the spread of the bow, substantially asdescribed.

4. A thermostat, comprising an iron bow -in contact with thebattery-Wire but' otherwise insu-lated and having its arms extendingtoward the indicator-wires, a set-screw through thebow for regulatingthe amount of spread of the arms, and copper bars rigidly secured to theinside of the arms and provided with angular toes or contact-points,substantially as described.

5. The thermostat herein described, consisting of the non-conductingback plate, the edge blocks provided with grooves to receiveindicator-wires, the iron bow having spreading arms, secured to the backplate in contact with the battery-wire, the copper bars :rigidly securedto the inside of the iron arms and having contact toes or points, andthe setscrew for regulating the spread of the bow, substantially asdescribed.

ROBERT J. BAKER.

Witnesses:

A. M. SPRonssER, JOHN R. Dovn.

